1. Field of the Invention
This invention relates to an improved hub construction of the collet-type and utilizes concentric telescopically engaged sleeve members with the inner sleeve member including a radial slot formed therethrough and the inner and outer sleeve members defining radially outwardly and radially inwardly opening step recesses, respectively, together defining a closed annular cavity between the sleeve members. Structure is provided for force shifting the sleeve members in opposite axial directions relative to each other and force direction change structure is contained within the cavity for developing a radial inward force on the inner sleeve member responsive to the sleeve members being forced in opposite radial directions relative to each other.
2. Description of Related Art
Various different forms of collet-type hubs and other structures including some general structural features similar to those included in the instant invention are disclosed in U.S. Pat. Nos. 2,003,144, 2,410,832, 3,367,727, 3,627,339 and 4,318,310. However, most presently used collettype hubs incorporate inner and outer sleeves provided with outer and inner mating conical surfaces and circumferentially spaced axially extending threaded fasteners are secured between the sleeves for relatively axially shifting the sleeves in a direction whereby the mating conical surfaces apply a radial inward thrust on the inner sleeve, the inner sleeve being provided with at leat one radial slot whereby it may be tightly clamped against an associated shaft extending therethrough. However, when it is desired to remove or reposition a hub of this type, the clamp fasteners used to axially shift the sleeves relative to each other in order to clamp the inner sleeve about an associated shaft must be completely removed and reinserted in special additionally threaded bores provided therefor whereby the inner and outer sleeves may be reversely axially shifted relative to each other in order to force the outer sleeve out of clamped engagement with the inner sleeve. Then, if the hub is to be reinstalled on the associated shaft, the fasteners must again be completely removed and reinstalled in their original positions in order that they again may be used to axially shift the sleeves relative to each other in order to clamp the inner sleeve above the associated shaft.
The removal of a plurality of threaded fasteners, the reinstallation of the threaded fasteners in different bores, the subsequent further removal of the threaded fasteners and the reinstallation of those threaded fasteners in the original bores is time consuming. Accordingly, a need exists for a collet-type hub which may be more readily released merely by the loosening the associated clamping screws.